JOIN USA global light pollution map developed by a group of researchers has ranked New Delhi, Kolkata and Bengaluru as the three cities with the highest light pollution in India. It should serve to alert us to the looming problem of light pollution about which we are not only doing so little to prevent but are also unaware about. Light pollution refers to the harmful impact of artificial outdoor lighting. While artificial outdoor lighting is needed in the form of street lights to increase safety on roads and enables us to study and work in the dark, its use for floodlighting, illumination, advertising, etc has grown manifold in recent decades, resulting in the problem of light pollution. Studies show that brightness from outdoor lights has risen steadily across India over a 20 year period, with New Delhi, Telangana, Maharashtra, Karnataka and Uttar Pradesh showing a “very high light pollution intensity” rise between 1993 and 2013.
The use of excessive artificial outdoor lighting has several harmful implications not just for human health but for the wellbeing of animals, birds and insects, and our environment. Use of artificial lights at night gives us more working and studying hours but it results in the problem of ‘loss of night.’ We find it difficult to fall asleep when the glow of streets enters our homes. It impacts our sleep-wake rhythm, which could have serious implications for our moods and health. Illumination of gardens impacts animals and insects too. It is nocturnal insects and birds that suffer the most due to light pollution. It makes them disoriented, impacts their reproduction and thus their populations.
There is little understanding or even awareness of the concept of light pollution, let alone its implications. But it is a problem that is quietly growing in magnitude. India, in particular, seems to be sleeping on the problem. A 2017 global study revealed that the ‘loss of night’ due to excessive artificial light at night is increasing three times faster in India than the global average. It is time India woke up to the light pollution problem before it overwhelms us. It is not difficult to tackle the issue. What we need to do is stop excessive use of illumination and floodlighting. Do we, for instance, need to play cricket matches at night under the full glare of floodlights? Lights must illuminate our streets, not the skies. Use of light for advertising should be regulated. Could we not make it mandatory for advertisers to switch off lights after a certain hour? But first, we need to realise that we need the dark as much as we need light.